Ok, I'm going to start by saying I'm in a similar(ish) situation and I know how you feel. I also got AAAB at AS and I want to go to Cambridge, then I discovered only 18% of applicants get in for my course.
Start with the easiest work you've got to do, or your favourite subject, get some decent music on and just chill whist working. You will clearly cope with A2s based on the grades you've got as long as you just carry on. Other people should be irrelevant to you, it doesn't matter how they feel, focus on yourself, it's your life.
That was a pretty **** pep talk, but to be honest it was better than my original reply of "lol, same here."